The single, titled Good Old Days, will appear on the 34-year-old rapper's upcoming solo album, Gemini. In Macklemore's latest musical effort, the Seattle native reflects on everything from his early career to his past struggles with substance abuse to his homecoming dance regrets.

At her Las Vegas concert on Saturday night, the songstress performed one of her faves — the female empowerment classic You Don't Own Me — but midway through took a moment to say a little something to the crowd.

And she used some language Lesley Gore probably wouldn't have gotten away with, saying:

Kelly Clarkson says you have to be real special for her not to like you — and Dr. Luke is just that kind of special.

The pair collaborated on Since U Been Gone and Behind These Hazel Eyes when she was first getting started, during which time she developed a real distaste for the hitmaker — who she said never tried anything with her like with Kesha, but was very demeaning.

"There are many people in the world to befriend, and he is not one of them."

Ha! But for Kelly, this beef was serious — serious enough to lose "hundreds of thousands" or even "millions" in royalties when RCA forced her to reunite with Dr. Luke for My Life Would Suck Without You!